fbsql_read_blob
(PHP 4 >= 4.2.0, PHP 5, PHP 7)
fbsql_read_blob — Read a BLOB from the database
说明
fbsql_read_blob (
string
$blob_handle [,
resource $link_identifier ] ) :
string
Reads BLOB data from the database.
If a select statement contains BLOB and/or CLOB columns FrontBase will return the data directly when data is fetched. This default behavior can be changed with fbsql_set_lob_mode() so the fetch functions will return handles to BLOB and CLOB data. If a handle is fetched a user must call fbsql_read_blob() to get the actual BLOB data from the database.
参数
-
blob_handle -
A BLOB handle, returned by fbsql_create_blob().
-
link_identifier -
由 fbsql_connect() 或 fbsql_pconnect() 返回的 FrontBase 链接标识符.
如可选并未指定，函数会尝试查找一个到 FrontBase 服务器的开放链接，且如没有找到这样的链接，会尝试通过不带参数调用 fbsql_connect() 来创建一个。
返回值
Returns a string containing the specified BLOB data.
范例
Example #1 fbsql_read_blob() example
<?php
$link = fbsql_pconnect("localhost", "_SYSTEM", "secret")
or die("Could not connect");
$sql = "SELECT BLOB_COLUMN FROM BLOB_TABLE;";
$rs = fbsql_query($sql, $link);
$row_data = fbsql_fetch_row($rs);
// $row_data[0] will now contain the blob data for the first row
fbsql_free_result($rs);
$rs = fbsql_query($sql, $link);
fbsql_set_lob_mode($rs, FBSQL_LOB_HANDLE);
$row_data = fbsql_fetch_row($rs);
// $row_data[0] will now contain a handle to the BLOB data in the first row
$blob_data = fbsql_read_blob($row_data[0]);
fbsql_free_result($rs);
?>
参见
- fbsql_create_blob() - Create a BLOB
- fbsql_read_clob() - Read a CLOB from the database
- fbsql_set_lob_mode() - Set the LOB retrieve mode for a FrontBase result set
